/**15 normal
 *
 */
/**
 * 遍历，去重，超时
 * @param {number[]} nums
 */
function threeSum(nums) {
  let result = [];
  const sums = [];
  for (let i = 0; i < nums.length; i++) {
    for (let j = i + 1; j < nums.length; j++) {
      sums.push({
        wait: 0 - nums[i] - nums[j],
        el: [nums[i], nums[j]],
        index: [i, j],
      });
    }
  }
  for (let i = 0; i < nums.length; i++) {
    sums.forEach((item) => {
      if (item.wait === nums[i] && !item.index.includes(i)) {
        result.push(item.el.concat(nums[i]));
      }
    });
  }
  let obj = {};
  result.forEach((item) => {
    item = item.sort((a, b) => a - b);
    obj[item] = item;
  });
  result = Object.values(obj);
  return result;
}

console.log(threeSum([-1, 0, 1, 2, -1, -4]));
console.log(1);

/**排序 遍历
 * 有限界不完全遍历
 * @param {number[]} nums
 * @return {number[][]}
 */
var threeSum = function (nums) {
  let ans = [];
  const len = nums.length;
  if (nums == null || len < 3) return ans;
  nums.sort((a, b) => a - b); // 排序
  for (let i = 0; i < len; i++) {
    if (nums[i] > 0) break; // 如果当前数字大于0，则三数之和一定大于0，所以结束循环
    if (i > 0 && nums[i] == nums[i - 1]) continue; // 去重
    let L = i + 1;
    let R = len - 1;
    while (L < R) {
      const sum = nums[i] + nums[L] + nums[R];
      if (sum == 0) {
        ans.push([nums[i], nums[L], nums[R]]);
        while (L < R && nums[L] == nums[L + 1]) L++; // 去重
        while (L < R && nums[R] == nums[R - 1]) R--; // 去重
        L++;
        R--;
      } else if (sum < 0) L++;
      else if (sum > 0) R--;
    }
  }
  return ans;
};
